1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vitek1552 [10]
3 years ago
12

Let c be a positive number. A differential equation of the form dy/dt=ky^1+c where k is a positive constant, is called a doomsda

y equation because the exponent in the expression ky^1+c is larger than the exponent 1 for natural growth. An especially prolific breed of rabbits has the growth term My^1.01. If 2 such rabbits breed initially and the warren has 16 rabbits after three months, then when is doomsday?
Mathematics
1 answer:
stich3 [128]3 years ago
4 0

Answer:

The doomsday is 146 days

<em></em>

Step-by-step explanation:

Given

\frac{dy}{dt} = ky^{1 +c}

First, we calculate the solution that satisfies the initial solution

Multiply both sides by

\frac{dt}{y^{1+c}}

\frac{dt}{y^{1+c}} * \frac{dy}{dt} = ky^{1 +c} * \frac{dt}{y^{1+c}}

\frac{dy}{y^{1+c}}  = k\ dt

Take integral of both sides

\int \frac{dy}{y^{1+c}}  = \int k\ dt

\int y^{-1-c}\ dy  = \int k\ dt

\int y^{-1-c}\ dy  = k\int\ dt

Integrate

\frac{y^{-1-c+1}}{-1-c+1} = kt+C

-\frac{y^{-c}}{c} = kt+C

To find c; let t= 0

-\frac{y_0^{-c}}{c} = k*0+C

-\frac{y_0^{-c}}{c} = C

C =-\frac{y_0^{-c}}{c}

Substitute C =-\frac{y_0^{-c}}{c} in -\frac{y^{-c}}{c} = kt+C

-\frac{y^{-c}}{c} = kt-\frac{y_0^{-c}}{c}

Multiply through by -c

y^{-c} = -ckt+y_0^{-c}

Take exponents of -c^{-1

y^{-c*-c^{-1}} = [-ckt+y_0^{-c}]^{-c^{-1}

y = [-ckt+y_0^{-c}]^{-c^{-1}

y = [-ckt+y_0^{-c}]^{-\frac{1}{c}}

i.e.

y(t) = [-ckt+y_0^{-c}]^{-\frac{1}{c}}

Next:

t= 3 i.e. 3 months

y_0 = 2 --- initial number of breeds

So, we have:

y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}

-----------------------------------------------------------------------------

We have the growth term to be: ky^{1.01}

This implies that:

ky^{1.01} = ky^{1+c}

By comparison:

1.01 = 1 + c

c = 1.01 - 1 = 0.01

y(3) = 16 --- 16 rabbits after 3 months:

-----------------------------------------------------------------------------

y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}

16 = [-0.01 * 3 * k + 2^{-0.01}]^{\frac{-1}{0.01}}

16 = [-0.03 * k + 2^{-0.01}]^{-100}

16 = [-0.03 k + 0.9931]^{-100}

Take -1/100th root of both sides

16^{-1/100} = -0.03k + 0.9931

0.9727 = -0.03k + 0.9931

0.03k= - 0.9727 + 0.9931

0.03k= 0.0204

k= \frac{0.0204}{0.03}

k= 0.68

Recall that:

-\frac{y^{-c}}{c} = kt+C

This implies that:

\frac{y_0^{-c}}{c} = kT

Make T the subject

T = \frac{y_0^{-c}}{kc}

Substitute: k= 0.68, c = 0.01 and y_0 = 2

T = \frac{2^{-0.01}}{0.68 * 0.01}

T = \frac{2^{-0.01}}{0.0068}

T = \frac{0.9931}{0.0068}

T = 146.04

<em>The doomsday is 146 days</em>

You might be interested in
If DAB = 80°, then DAC =
vodka [1.7K]

Answer:

80

Step-by-step explanation:

DAB =DAC...........

6 0
2 years ago
Read 2 more answers
What is the sum of the arithmetic sequence 3, 9, 15…, If there are 34 terms?
snow_tiger [21]

Answer:

first we find the common difference.....do this by subtracting the first term from the second term. (9 - 3 = 6)...so basically, ur adding 6 to every number to find the next number.

we will be using 2 formulas....first, we need to find the 34th term (because we need this term for the sum formula)

an = a1 + (n-1) * d

n = the term we want to find = 34

a1 = first term = 3

d = common difference = 6

now we sub

a34 = 3 + (34-1) * 6

a34 = 3 + (33 * 6)

a34 = 3 + 198

a34 = 201

now we use the sum formula

Sn = (n (a1 + an)) / 2

S34 = (34(3 + 201))/2

s34 = (34(204)) / 2

s34 = 6936/2

s34 = 3468 <=== the sum of the first 34 terms:

6 0
3 years ago
The perimeter of a rectangle is 234 cm. If the width is 51 cm,what is the length?
Reil [10]

The length will be 66 cm

3 0
3 years ago
Read 2 more answers
Please answer correctly !!!!!!!!! Will<br> Mark brainliest !!!!!!!!!!!!!
il63 [147K]

Answer:

x=-\frac{-20+\sqrt{-20w+3600}}{10},\:x=-\frac{-20-\sqrt{-20w+3600}}{10}

Step-by-step explanation:

w=-5\left(x-8\right)\left(x+4\right)\\\mathrm{Expand\:}-5\left(x-8\right)\left(x+4\right):\quad -5x^2+20x+160\\w=-5x^2+20x+160\\Switch\:sides\\-5x^2+20x+160=w\\\mathrm{Subtract\:}w\mathrm{\:from\:both\:sides}\\-5x^2+20x+160-w=w-w\\Simplify\\-5x^2+20x+160-w=0\\Solve\:with\:the\:quadratic\:formula\\\mathrm{Quadratic\:Equation\:Formula:}\\\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}\\x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}

\mathrm{For\:}\quad a=-5,\:b=20,\:c=160-w:\quad x_{1,\:2}=\frac{-20\pm \sqrt{20^2-4\left(-5\right)\left(160-w\right)}}{2\left(-5\right)}\\x=\frac{-20+\sqrt{20^2-4\left(-5\right)\left(160-w\right)}}{2\left(-5\right)}:\quad -\frac{-20+\sqrt{-20w+3600}}{10}\\x=\frac{-20-\sqrt{20^2-4\left(-5\right)\left(160-w\right)}}{2\left(-5\right)}:\quad -\frac{-20-\sqrt{-20w+3600}}{10}\\The\:solutions\:to\:the\:quadratic\:equation\:are\\x=-\frac{-20+\sqrt{-20w+3600}}{10},\:x=-\frac{-20-\sqrt{-20w+3600}}{10}

6 0
3 years ago
What is the b in this math question -17+b/8=1
brilliants [131]
Are you supposed to find B?
5 0
3 years ago
Other questions:
  • How to plot y=1/2x + 2​
    7·1 answer
  • What is the slope of the graph?
    8·1 answer
  • write two linear functions, f(x) and g(x). For example, f(x)= 3x-7 and g(x)= -2x+5. Then see whether f(x) - (-g(x)) is equivalen
    6·1 answer
  • 1. If one zero of the quadratic polynomial kx² + 3x + k is 2 then the value of k is *
    14·1 answer
  • William has a 22 ounce energy drink. He drinks 12 ounces. Enter the percentage of ounces William has left of his energy drink. R
    9·1 answer
  • The area of a rectangular field is 5785 m(squared)
    13·2 answers
  • Chris has 2 pairs of black socks, 4 pairs of red socks, and 18 pairs of white socks in a dresser drawer. What is the probability
    6·2 answers
  • Is -1/5 the same thing as 1/-5​
    7·2 answers
  • Can u pls help me with this question ​
    6·1 answer
  • Determine whether the given graph is a function or not.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!